Preheat oven to 350°F. Butter and then flour 9- x 13-inch baking dish. Line with foil or parchment paper; then spray with no-stick cooking spray and set aside.

Prepare the batter: In a large bowl, combine all of the Cookie ingredients; mix until well combined. Batter will be thick; pour into the prepared baking dish and use clean, slightly moistened fingers to press into dish, as necessary.

Prepare the Topping: Mix together all of the topping ingredients; sprinkle over the batter.

Bake: In preheated oven until a toothpick inserted in the center comes out clean, about 20 to 25 minutes. (The bars may appear slightly under-cooked.)

Prepare the Glaze: Meanwhile, mix together all of the ingredients, slowly adding the milk (or cream) until reaching desired consistency. Spread over warm (not hot) cookie. Cool for 10 to 15 minutes before lifting out of baking dish; then cool completely before cutting into bars and serving.